Is TMX all there is?

Arvee · Dec 20, 2006

I was reading the digital vs. film comparison at clarkvision.com and noted that TMX theoretically represents the best one can achieve in a 35mm continuous tone B/W film and is about equivalent to a good quality 6 mp digital camera. I am able to confirm this fact myself using rudimentary testing.

Short of using TechPan, is there any other B/W product or film/dev combo that will compete with the performance of Velvia 50 in 35mm? (Velvia 50 is up there equal to the 12-16 mp cameras.)

Shoot Velvia 50 and convert to B/W in PS?

I don't intend to abandon film in the near future but I was amazed to discover the quality of the e-products coming on the market.

Ron

David A. Goldfarb · Dec 20, 2006

If you want finer grain, richer tonality, and better resolution, use a bigger camera.

Arvee · Dec 20, 2006

Thanks, David, I already have a Pentax 67 that does a good job but my right arm is now about 6" longer than my left. I'd like that problem to go away!

Of course, I could also get a field camera and never hike farther than the back of my pickup as Ansel did with his Caddymobile.

Ron

Paul Howell · Dec 20, 2006

I have not any testing at all, I have a 12 mega pixal digital SLR, and I can tell you that in my subjective experice Pan F, Adox 25, Plus X, FP4, full frame 35 beat my digital SLR up to 16X20. My 6X6 and 6X9 MF beat my DSLR with any film fast or slow, and 4X5, not even in the same league.

Michel Hardy-Vallée · Dec 20, 2006

Fred Aspen said:
theoretically represents the best in a continuous tone B/W film ...

Two words you should be careful of when using photo products: "theoretically" and "the best."

Theoretical performance means nacht if someone has crappy technique. Photo quality is a multi-variable concept, so even if every qualitative aspect was quantifiable, you could still not line up photo products on a single scale.

That also explains why there are many different types of film on the market because taste and purpose are two factors more important than a concept like "ultimate quality".

Think of photo more like cooking than SAT testing. Would a concept like "the best flour ever on the market" make any sense to you?

jstraw · Dec 20, 2006

So many variables are introduced when making decisions about how to develop a roll of TMX that finding it's maximum resolving power is not a simple task. I'm sure someone here has done some work in that area. Finding the analogous X megapixels of resolution would have to take place *after* determining it's own, hypothetical maximum.

Photo Engineer · Dec 20, 2006

I don't know how they can rate these digital cameras so high. The imaging sensors are a lot larger than the largest film grain, and there are fewer of them per unit area. In addition, the aliasing in the image due to the side by side color sensors which is not present in film will lower resolution, raise grain and distort the image.

Much of this is false information in the sense that the image is manipulated by software in the camera to fix, as much as possible, the errors in the image.

An example would be to take a picture of a window screen lit heavily by sunlight. With film, you will see the fine mesh, but with digital you will most likely see a moire patter superimposed on the image. This is something that cannot be removed by software all of the time.

In addition, there is a fine mesh filter over the sensors intended to assist in decreasing apparent grain, and also to decrease IR sensitivity. This slight IR sensitivity also distorts color. If it were not there, the color would be very distorted. Many people remove this screen to enhance the IR sensitivity of digital equipment and also to enhance the ability to photograph with these distortions.

PE

Alan Johnson · Dec 20, 2006

Here is the MTF chart for T-max 100:
http://www.kodak.com/global/en/professional/support/techPubs/f4016/f002_0542ac.gif
The Canon 5D sensor (12.8m-pixel) has a resolution of 50-80 lppm but its contast then drops off rapidly.It looks smoother though.

BradS · Dec 20, 2006

Fred Aspen said:
I don't intend to abandon film in the near future but I was amazed to discover the quality of the e-products coming on the market.

Ron

I guess it depends upon how you define "quality". When I look at portraits made with 100 year old lenses and 8x10 view cameras, they have a quality which, I dare say cannot be replicated by any modern equipment, method or software.

Look beyond the numbers and the sanitized scientific analysis. Look for the soul. Digital photos, no matter how many MegaPixels, lack soul.

Arvee · Dec 20, 2006

Well said, Brad! That is precisely why I won't let go of film. Too many years breathing fix!

Ron

Photo Engineer · Dec 20, 2006

Alan Johnson said:
Here is the MTF chart for T-max 100:
http://www.kodak.com/global/en/professional/support/techPubs/f4016/f002_0542ac.gif
The Canon 5D sensor (12.8m-pixel) has a resolution of 50-80 lppm but its contast then drops off rapidly.It looks smoother though.

Alan, the digital result is enhanced and smoothed via software.

I have examples to show, but they are not appropriate for APUG.

PE

Reinhold · Dec 20, 2006

mhv said:
Two words you should be careful of when using photo products: "theoretically" and "the best."

Amen.

Reinhold

www.classicbwphoto.com

wirehead · Dec 20, 2006

Well, you have to remember that film grain is on/off, wheras a digital sensor is a numerical value. So you cannot compare size-of-film-grain to size-of-sensor-area. IIRC, all things being equal, digital is more efficent in terms of photons-captured.

One thing that Ken Rockwell pointed out, and this is a case where he's totally on the mark, is that you can't rely solely on horizontal-and-vertical lines to really measure resolution of a digital sensor.

You also have to remember that if you shoot a dSLR and either use a red filter over the lens or apply a red filter in post, you are only using 1 out of every 4 sensor elements.

There's a lot of corner cases. They could make a 20-30 megapixel 24x36mm sensor, except it would only look good at ISO 100, and half the advantage of dSLRs is that they are really clean at ISO 400 and above. On the other hand, a 4x5 and a few boxes of quickloads and a flatbed is going to be a lot cheaper than the 40 megapixel 645 backs and either one can be blown up huge.

I bought an RB67 so I wouldn't want to buy a EOS 5D.

Rob Archer · Dec 20, 2006

My maths and terminology may be totally off-beam here, but I understand that on the Basis that Ilford Delta 100 has a theoretical (sorry, that word again!) resolution of at least 100 Line-pairs per mm, that gives a linear resolution of 200 units of resolution per mm. If that can be equated to pixels, then Delta 100 in 35mm has the equivelent resolution of 7200 x 4800, or roughly the same resolution as a 34.5 megapixel digital camera. I've always been led to believe that lens resolution is the limiting factor anyway.

Somebody please tell me if I've got this totally wrong (I'm sure somebody will!)

Rob

Photo Engineer · Dec 20, 2006

Rob;

You are closer to being correct.

In fact, if you scan a 35 mm film negative or slide at high resolution and apply the same smoothing algorithms to the scanned product, you get a result that blows digital out of the water for grain and sharpness. But, this requires a rather sophisticated user and some fancy software.

PE

Ryuji · Dec 20, 2006

T-MAX 100 and Acros give about the same resolution, but Acros tends to give better accutance in most developers. T-MAX 100 can give good accutance in some developers, such as DS-12, but it generally give images that lack visual accutance compared to most other films, which I suspect why this film is rather unpopular.

Velvia 50 or Velvia 100F is a fine film, but either of them deliver significantly lower resolution compared to 100-speed tabular grain b&w films. Generally speaking, color films deliver significantly lower resolution than b&w films for the same speed.

There is no single valid method to convert film resolution to equivalent megapixel ratings. Most common way is to determine the spatial frequency at which MTF is 50% for a given contrast and use this value to convert equivalent pixels. However, this method underrates the "capacity" of the film considerably.

Incidentally, one of my recent film developer allows me to shoot 35mm Acros at EI 80 or 100, and I can make virtually grainless 20x24 prints from it. When compared to making same print from medium format, the image quality is visibly inferior, but better than digital for sure.

Photo Engineer · Dec 20, 2006

I would rank order from worst to best at equal magnification from the original, digital (8 MP Nikon D70), Negative print from 35mm, Negative print from MF, any chrome or negative scanned at high resolution, manipulated and digitally printed.

PE

reub2000 · Dec 20, 2006

I don't see the reason to try and calculate a mega pixel value for film. Film does not capture an image as a matrix of pixels.

And if your scanning your negatives, you should try printing with an enlarger. It's fun.

Tom Stanworth · Dec 21, 2006

I say exploit the benefits of film and dont worry too much about where digital scores points. The benefits of film are in the character of the final product and the fidelity associated with a film based print. Go for a film that gives you the soul you want and screw whether a didital image looks 'smoother'. I have yet to see a digital capture based print that has any of the soul of a great film image. Enjoy the fact that your film images represents real stuff. I know on the few occassions I have exhibited and sold my work this has mattered to the public too. I believe digital and mono film have very little in common; both form an image but then again so does a painting.

If you want fine grain I would suggest delta 100 or acros, but not tmax100. This last fiml IMO has little acutance and is no soul. soup any fine grained film in perceptol or xtol and the grain is tough to find.

dancqu · Dec 21, 2006

Rob Archer said:
I've always been led to believe that lens
resolution is the limiting factor anyway. Rob

Led rationaly I believe. What matter the "resolution" of
the sensor if it's area is little. With that little area there is
an appropriate short Normal focal length.

One thousand lines per mm on a sensor all of 12x18 mm.
Were it so what good would it be? A good quality lens will
deliver no more than one hundred or a few more.

I've do think though, given good optics, that the sensors
are shy of doing them justice. Dan

JBrunner · Dec 21, 2006

Comparisons such as this are inherently flawed, apples to oranges and all that. Its really a comparison of a d thingie and a scanner.

It is also a matter of taste, and if you have any taste at all, its not hard to find the clear winner.

haryanto · Dec 21, 2006

Like Barnbaum said:"nothing has the radiance of a finely crafted silver print. Nothing."

and

The Saints Ansel: " Nothing beat a Silver Print"

I think that if you want to compared it, compared it in print side by side

Is TMX all there is?

Arvee

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